What Is Flavour?

“Flavour: how food or drink tastes, or a particular taste itself (Cambridge Dictionary, 2024).”

Flavour, taste, palate, character – such terms are used interchangeably to describe what is essentially the same thing – an experience that happens inside one’s head. Is it any surprise, therefore, that an unsavoury amount of confusion exists around the question of ‘what is flavour’?

Surely it should be a simple enough thing to answer. After all, flavour forms a valuable component of everyday life. It’s part pleasure, part nutritional, and for those in the food and drink industry, it’s part vocation. But once we begin to tackle the question, it becomes increasingly evident how much we take for granted when it comes to flavour. We can become so focused on why tipples and nibbles taste a certain way, that we forget to pause and consider what flavour actually is?

Is taste the same as flavour?

Anyone who's tried the sensory experiment of sipping a drink using one hand while pinching one’s nostrils with the other, will know the disappearing act of flavour. Yet as soon as the nostrils are released by your digits, “Abracadabra Alakazam”, the flavour magically appears. It’s also why ‘taste’ is reduced when one catches a cold. But if flavour has a lot to do with smell, what is taste?

It's intriguing how we casually interchange taste and flavour. We can enjoy a product’s ‘flavour’ at a ‘tasting’. In fact, a drink may well even be tasty and flavoursome. But why does unsalted food seem tasteless, yet salt enhances its flavour? It’s no wonder that so much confusion exists around these terms.

Taste, as a sense, is of course how we experience sweet, salty, sour, bitter, umami, and possibly fatty too (perhaps others even). A rather simple array of sensations when compared to the encyclopaedia of different aromas that the nose can detect. So in such terms it would seem that flavour is very much more than the five or six things we can taste. Certainly, odours add many more layers to the conundrum than tastes could ever dream of.

Aroma, taste, and mouthfeel

Combined, aromas and tastes make up a large proportion of flavour, but mouthfeel (chemesthesis and somatosensation) plays an important role too. Mouthfeel is often relegated behind the more centre stage performances of aroma and taste, but mouthfeel is crucial for making flavours complex, interesting, and exciting for the brain. Imagine wine without tannins, cream without fat, or sparkling wine without mousse. You can learn all about mouthfeel here, it’s fascinating: Mouthfeel: The Unspoken Hero.

Therefore, this is all taken into account in the definition of flavour that is accepted by the scientific community. From the ASTM International standards:

“Flavor, n—(1) perception resulting from stimulating a combination of the taste buds, the olfactory organs, and chemesthetic receptors within the oral cavity; (2) the combined effect of taste sensations, aromatics, and chemical feeling factors evoked by a substance in the oral cavity.”

This is a comprehensive, to-the-point explanation of flavour, however, it’s easy to overlook a single word that has perhaps more significance than any others – perception.

The perception of flavour

Perception is the awareness of elements in the environment through sensory stimulation. It happens when the brain takes sensory information and organises it into meaningful assessments of the world around us. With regards to eating and drinking, the brain combines odours, tastes, and mouthfeel, to construct the concept of flavour.

There’s a general misconception that flavour is an absolute quality that exists beyond sensory experience. For example, if a drink is made from a mixture of the chemicals x, y, and z, it should be expected to taste a certain way. But on its own the drink will taste of nothing. The flavour of it will only emerge once it’s entered the mouth the brain creates the sensation based on sensory stimulation. For the large part this is predictable and replicable.

However, we all have different genes, different life experiences, and different brains. So how something will taste to you may be different to how it will taste to I. There’s no way of telling for sure unless the difference is radical, as can be the case with coriander (cilantro). Yes the delicious green herb. Or is it a disgusting soapy herb?

Due to genetic variation coriander tastes unpalatably soapy and bitter to some people (so I’m told). But it raises the question – is coriander tasty or obnoxious? Both, it would seem. The point is that it’s all a matter of perception, and as perception is created by the brain, this clump of neurons has the power to determine how things taste.

Flavour as a system of pleasure

In a nutshell, flavour is the result of stimulation of the olfactory receptors (smell), taste buds, and the various sensations of mouthfeel, as interpreted by the brain. The close relationship between all four elements occurs so autonomously and simultaneously that anyone would be forgiven for simply calling it taste. Flavour then, can be considered as a system. It’s quite a complex system though.

As a system it is the integration of sensory information in the brain, but going one step further, the purpose of this integration is to create a hedonic experience. That is to experience something pleasurable. We don’t just perceive individual tastes and smells separately but as a unified, often pleasurable experience. This hedonic response is usually the first and strongest reaction we have to food and can influence whether we accept it or reject it.

The question is, can we therefore view flavours as units of pleasure? Whether you are a dedicated follower of flavour, or an innocent bystander, the association between drinks reviews and scoring systems will undoubtedly be familiar. It would seem then, that flavour can be given a hedonic score, because surely a review or medal award is nothing more than how much someone enjoyed a flavour?

But just when we thought we were getting somewhere, there’s a considerably sized spanner we must throw into the wheels.

What is flavour?

Of course, the perception of flavour is far more than taste, smell, and mouthfeel alone. Visual cues play a powerful role, and we can be misled simply by changing a product’s colour. The shape of the glass, the design of the plate, the packaging, the feel of the cutlery, and even the sound of the environment can all shift what we think we are tasting.

But flavour is not only multisensory; it is also deeply top-down. Our expectations, formed by memory, previous experience, branding, presentation, and context, help shape the flavour we perceive before the first sip or bite even reaches consciousness. As it turns out, the brain creates an expectation and then not only matches the sensory inputs against it, but can also adjusts the sensory inputs if they do not align with the expectation. Find out more about how this works here: Why Flavour Is More Prediction Than Perception.

In that sense, flavour is not just received from the product, it is actively constructed by the brain. Fatigue, satiation, and emotional state such as anxiety, relaxation, or stress, can all further influence the experience.

Hence, when attempting to define flavour, drawing a clear boundary around it becomes increasingly challenging.

Can we define flavour?

Flavour resists a clear definition because it is not a single thing, but an evolving experience assembled from many sources at once. Taste, aroma, texture, temperature, vision, sound, and even the setting in which we consume a product all contribute to what we perceive. Once these inputs begin to interact, the boundaries between them stop being distinct, and flavour becomes less like a component we can isolate and more like an outcome we experience.

But it’s not just about inputs. Emotions, satiation, cellular function, and circadian rhythms come into play too. And we haven’t even touched on microbiome yet. The microbes that inhabit your skin and digestive tract have a much larger sway over the perception of flavour than many even consider.

The problem becomes even more complex when we consider that flavour is shaped by prediction. The brain does not wait passively for sensory data and then simply record it; it generates expectations from memory, learning, branding, appearance, and context, and then uses incoming sensory information to confirm or adjust that expectation. In that sense, what we call flavour is partly sensation and partly inference, i.e. a constructed judgement rather than a direct readout of the product itself.

That is why any definition of flavour is inevitably incomplete. A strict sensory definition may describe the inputs, but it cannot fully capture the psychological and contextual forces that shape the final experience, while a broader definition risks becoming so wide that it loses precision. Flavour may therefore be best understood not as a fixed category, but as a fluid perceptual event whose edges are always blurred.

Everyone will have their own meaning, which will be dependent on how they interact with flavour, either in a professional or personal context. On a basic level the ASTM definition seems to surfice, but research has moved on and our understanding has moved on. While an updated definition may struggle to progress beyond flavour being the multi-modal perception of consumption, unpacking the challenge broadens our understanding of products and how the experience of them must be considered beyond formulation alone.